outkat (k-rate aftertouch output) sends aftertouch messages. It works only with MIDI instruments which recognize them. It can drive a different value of a parameter for each note currently active.

It can scale the k-value floating-point argument according to the kmin and kmax values. For example: set kmin = 1.0 and kmax = 2.0. When the kvalue argument receives a 2.0 value, the opcode will send a 127 value to the MIDI OUT device. When the kvalue argument receives a 1.0 value, it will send a 0 value. k-rate opcodes send a message each time the MIDI converted value of argument kvalue changes.